Portable engine generators having an engine, a generator and a fuel tank arranged in a housing are widely used. To improve operability when starting the engine, some of such engine generators are configured such that a starter handle which is an operating portion of the recoil starter of the engine, a choke operating portion which is an operating portion of the choke valve, and a cock operating portion which is an operating portion of the fuel cock provided to the fuel pipe connecting the fuel tank and the engine with each other are positioned close to each other and arranged in a prescribed region of a side face of the housing (for example, JP2006-161692A). In these engine generators, the choke valve and the choke operating portion are connected by a push-pull cable to provide the choke operating portion on the side face of the housing. Further, to provide the cock operating portion on the side face of the housing, a part of the fuel pipe is disposed in the vicinity of the side face of the housing and the fuel cock is provided to this part.
In an engine that requires manual operation of the choke operating portion when starting the engine, it is necessary to return the choke operating portion to the initial position by manual operation after the engine is warmed up. If this operation is forgotten, the engine may be operated at an air-fuel ratio that results in excessive fuel, leading to deterioration in fuel efficiency and/or engine stall. To enable such a choke operation to be omitted, various automatic choke systems have been conceived (for example, JP2007-162576A).
However, the automatic choke systems as disclosed in JP2007-162576A are complex in structure and have many component parts, which results in a higher cost and lower serviceablity. Further, users cannot engage in the choke operation in the automatic choke systems, and this may be frustrating to users who want to operate the choke themselves. For this reason, it would be preferred that the users are allowed to manually operate the choke while the system automatically adjust the air-fuel ratio to compensate for any deficiencies caused by the manual operation, to thereby suppress occurrence of engine stall or the like. Also, if a half choke (half open) and a full choke (fully closed) can be selected depending on situations, such as when the engine is cold or after a long period of storage, the startability of the engine is improved.